X-ray phase imaging apparatus

Abstract

The X-ray phase imaging apparatus includes a position switching mechanism for switching a relative position of one or more gratings between a retreated position which is an outside of a detection range on a detection surface of an image signal detector and a detection positon which is an inside of the detection range on the detection surface of the image signal detector and a focal diameter changing unit configured to change a focal diameter of the X-ray source in conjunction with switching of the relative position of the one or more gratings.

The invention claimed is: 
     
       1. An X-ray phase imaging apparatus comprising:
 an image signal generation system including an X-ray source and an image signal detector for detecting an image signal based on an X-ray irradiated from the X-ray source; 
 one or more gratings arranged between the X-ray source and the image signal detector; 
 a position switching mechanism configured to relatively move at least either the image signal generation system or the one or more gratings to switch a relative position of the one or more gratings between a retracted position which is an outside of a detection range on a detection surface of the image signal detector and a detection position which is an inside of the detection range on the detection surface of the image signal detector; and 
 a focal diameter changing unit configured to change a focal diameter of the X-ray source itself by changing a focus control of the X-ray source, in conjunction with switching of the relative position of the one or more gratings. 
 
     
     
       2. The X-ray phase imaging apparatus as recited in  claim 1 , wherein
 the one or more gratings include two gratings, the two gratings including a self-image forming grating for forming a self-image by being irradiated by the X-ray from the X-ray source and an interference fringe forming grating for forming an interference fringe with the self-image of the self-image forming grating by being irradiated by the X-ray passed through the self-image forming grating, and 
 the position switching mechanism switches at least either the self-image forming grating or the interference fringe forming grating between the retracted position and the detection position. 
 
     
     
       3. The X-ray phase imaging apparatus as recited in  claim 1 , wherein
 the one or more gratings include three gratings, the three gratings including a coherence enhancing grating for enhancing coherence of the X-ray irradiated from the X-ray source, a self-image forming grating for forming a self-image by being irradiated by the X-ray passed through the coherence enhancing grating, and an interference fringe forming grating for forming an interference fringe with the self-image of the self-image forming grating by being irradiated by the X-ray passed through the self-image forming grating, and 
 the position switching mechanism switches at least either the coherence enhancing grating or the interference fringe forming grating between the retracted position and the detection position. 
 
     
     
       4. The X-ray phase imaging apparatus as recited in  claim 1 , wherein
 the one or more gratings include one grating which is a self-image forming grating for generating a self-image by being irradiated by the X-ray from the X-ray source, and 
 the position switching mechanism switches the self-image forming grating between the retracted position and the detection position. 
 
     
     
       5. The X-ray phase imaging apparatus as recited in  claim 1 , wherein
 the one or more gratings include two gratings, the two gratings including a coherence enhancing grating for increasing coherence of the X-ray irradiated from the X-ray source and a self-image forming grating for forming the self-image by being irradiated by the X-ray passed through the coherence enhancing grating, and 
 the position switching mechanism switches at least either the coherence enhancing grating or the self-image forming grating between the retracted position and the detection position. 
 
     
     
       6. The X-ray phase imaging apparatus as recited in  claim 1 , wherein
 a plurality of gratings is provided, and 
 the position switching mechanism switches all of the plurality of gratings between the retracted position and the detection position. 
 
     
     
       7. The X-ray phase imaging apparatus as recited in  claim 1 , wherein
 the position switching mechanism moves at least either the image signal generation system or the one or more gratings in a horizontal direction orthogonal to an optical axis direction of the X-ray or a vertical direction to switch the relative position of the one or more gratings between the retracted position and the detection position. 
 
     
     
       8. The X-ray phase imaging apparatus as recited in  claim 1 , further comprising a moving mechanism for changing a distance between the X-ray source and the image signal detector in conjunction with switching of the relative position of the one or more gratings. 
     
     
       9. The X-ray phase imaging apparatus as recited in  claim 1 , further comprising a rotation mechanism for relatively rotating an object and either the image signal generation system or the one or more gratings in a rotational direction about a central axis of a vertical direction orthogonal to an optical axis direction of the X-ray.